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71.
Meredith F. Small 《International journal of primatology》1981,2(1):91-95
Using weight and skinfold thickness to calculate relative body fat, the fat content of 21 captive female rhesus macaques was
estimated. Although age and. pregnancy had no effect on fat, rank was significant, especially during winter, with high-rank
females having the highest fat scores. Rank therefore has a significant effect on the health of captive animals and may also
affect the health of individuals in feral groups. 相似文献
72.
Growth of liver accompanied by an increased binding of aminoacyl-transfer ribonucleic acids. 下载免费PDF全文
Homogenates of rat liver obtained 3 or 14 days after partial hepatectomy were used to prepare the postmicrosomal pH5-supernatant fraction and to prepare salt-wash fractions of the 40S ribosomal subunits and the 80S ribosomes. The factor-dependent binding of methionyl-tRNAfMet to ribosomes and the elongation-factor-1-dependent binding of phenylalanyl-tRNA to ribosomes were both increased after 3 days of growth, but not after 14 days of growth. An activity inhibitory to phenylalanyl-tRNA binding that was located in ribosomal wash fractions was decreased after 14 days of growth. Since the decreased inhibitory activity was obtained from the ribosomes and was tested against ribosomes and excess of pH5-supernatant fraction from control rat liver, its action was separate from the phenylalanyl-tRNA binding activities of the pH5-supernatant fractions from sham-operated and regenerating liver. 相似文献
73.
Effects of low temperature on respiration and uptake of rubidium ions by excised barley and corn roots 总被引:5,自引:4,他引:1 下载免费PDF全文
The effect of temperature upon ion uptake and respiration was investigated with excised roots of corn (Zea mays) and barley (Hordeum vulgare). A strong inhibition (Q10 = 5 to 8) of ion uptake was observed at temperatures below 10 C. At higher temperatures more normal temperature dependencies (Q10 = 1.3 to 2) were obtained. When the data were plotted according to the Arrhenius relationship, two different activation energies were indicated above and below 10 C. Other studies have related such changes with temperature in activation energy of processes to changes in membrane properties induced by temperature. These results suggest that such phase transitions may affect ion uptake processes. If so, then differences among species in their capacity to maintain normal root function at low soil temperature and to resist low temperature stress may be related to differences in the physical properties of cellular membranes. 相似文献
74.
K Hoffken I D Meredith R A Robins R W Baldwin C J Davies R W Blamey 《BMJ (Clinical research ed.)》1977,2(6081):218-220
In a retrospective study in women with breast cancer circulating immune complex levels were measured by radioimmunoprecipitation with 125I-Clq. Before operation all the patients showed plasma immune complex levels significantly higher than those in controls. Twelve months after mastectomy patients identified clinicopathologically as having a good prognosis had almost normal levels of immune complexes. By contrast, patients with detectable dissemination on diagnosis or those who died within 22 months after mastectomy had significantly raised plasma levels. The tumour-specific nature of the immune complexes detected remains to be shown and suggestions about the applicability of this test not only for prognosis but also for monitoring the course of malignant diseases need to be confirmed by further investigations. 相似文献
75.
The report of R. J. Gillies, M. P. Rosenberg, and D. W. Deamer (1981, J. Cell. Phys., 108, 115–122) that sea urchin fertilization acid is anaerobically produced CO2, was reinvestigated by inseminating Strongylocentrotus purpuratus eggs in HCO?3-free seawater, then bubbling the seawater with N2 to remove volatile acid. Fertilization acid production occurred in HCO?3-free seawater and with N2-bubbling, the pH rose 0.28 ± 0.08 unit, significantly less than the rise of 0.63 ± 0.14 unit during N2-bubbling of HCO?3-free seawater that had been acidified with CO2 and similar to the rise of 0.18 ± 0.07 unit when acidification was with HCl. We conclude that most, if not all, of the sea urchin fertilization acid is nonvolatile and thus is not CO2; since it is not a weak acid, it must be H+. 相似文献
76.
A review of the salt sensitivity of the Australian freshwater biota 总被引:13,自引:7,他引:6
Barry T. Hart Paul Bailey Rick Edwards Kent Hortle Kim James Andrew McMahon Charles Meredith Kerrie Swadling 《Hydrobiologia》1991,210(1-2):105-144
In Victoria, Australia, both dryland salinity and salinity in irrigation regions are serious agricultural problems. One option
to control the latter is to pump groundwater to maintain it below the surface. However, this leaves a saline wastewater for
disposal, probably into local streams or wetlands. This review of the salt sensitivity of the biota of Australian streams
and wetlands gives information of interest to those responsible for developing controls on these discharges. The review addresses
the lethal and sub-lethal effects of salinity on microbes (mainly bacteria), macrophytes and micro-algae, riparian vegetation,
invertebrates, fish, amphibians, reptiles, mammals, and birds. Data suggest that direct adverse biological effects are likely
to occur in Australian river, stream and wetland ecosystems if salinity is increased to around 1 000 mg L−1. The review highlights a general lack of data on the sensitivity of freshwater plants and animals to salinity increases. 相似文献
77.
M Carey J Kolman D A Katz L Gradoville L Barberis G Miller 《Journal of virology》1992,66(8):4803-4813
78.
79.
We have used phase-contrast microscopy to determine a necrotic end point of the order of minutes in primary hepatocytes exposed to oxyradicals generated with xanthine oxidase plus hypoxanthine. This study examines whether the morphologic end point thus determined agrees with other criteria of cell necrosis. When 95-100% of the cells were shown to be necrotic by our morphologic assay, transmission electron microscopy confirmed definitive subcellular evidence of cell death, trypan blue exclusion revealed a 92% loss in the ability of cells to exclude the dye, and there was a 47% specific release of 51Cr (versus a 50% theoretical value). In contrast, the appearance of extracellular aspartate aminotransferase activity was relatively slow and did not corroborate the morphologic end point. In summary, we have validated the morphologic end point in our cell-based assay of oxyradical damage. 相似文献
80.
Unusual proteolysis of the protoxin and toxin from Bacillus thuringiensis. Structural implications 总被引:4,自引:0,他引:4
C T Choma W K Surewicz P R Carey M Pozsgay T Raynor H Kaplan 《European journal of biochemistry》1990,189(3):523-527
Trypsin is shown to generate an insecticidal toxin from the 130-kDa protoxin of Bacillus thuringiensis subsp. kurstaki HD-73 by an unusual proteolytic process. Seven specific cleavages are shown to occur in an ordered sequence starting at the C-terminus of the protoxin and proceeding toward the N-terminal region. At each step, C-terminal fragments of approximately 10 kDa are produced and rapidly proteolyzed to small peptides. The sequential proteolysis ends with a 67-kDa toxin which is resistant to further proteolysis. However, the toxin could be specifically split into two fragments by proteinases as it unfolded under denaturing conditions. Papain cleaved the toxin at glycine 327 to give a 34.5-kDa N-terminal fragment and a 32.3-kDa C-terminal fragment. Similar fragments could be generated by elastase and trypsin. The N-terminal fragment corresponds to the conserved N-terminal domain predicted from the gene-deduced sequence analysis of toxins from various subspecies of B. thuringiensis, and the C-terminal fragment is the predicted hypervariable sequence domain. A double-peaked transition was observed for the toxin by differential scanning calorimetry, consistent with two or more independent folding domains. It is concluded that the N- and C-terminal regions of the protoxin are two multidomain regions which give unique structural and biological properties to the molecule. 相似文献